Using HTML for input

Using HTML for input

If I add a button to an HTML snippet on a page, how can I trigger an action when it is clicked?
  1. <button onclick=???>Click Me</button>
I've tried calling a script within the HTML, and I've tried calling a Deluge function, but neither seems to do anything.  Can anyone point me at a relevant help guide or video please?  All the ones I have seen focus on making outputs look beautiful, but I need to format input using elements that aren't available in Creator forms.